1999 16ft Polar Kraft Conversion Project

[MiClayton38]

Hello Everyone, this is my 1st post on and here and so far and have enjoyed looking at the projects that are posted on here! It's amazing what you can turn a jon boat into! I recently purchased a 1999 16ft Polar Kraft 1648 with a 15hp and want to mod it a little. I'm not wanting to do anything major but just a few things to make it a little more functional. I am wanting to add a small casting deck that will not connect to the middle bench on the front so I can leave some leg room for the middle bench. And also I am wanting to carpet the floor and benches.

My question is this: How much does the weight affect the performance after adding the wood and carpet? My boat runs very well with me and an adult passenger but my concern is after adding the few things that I listed above that I will have trouble possibly getting the boat to plane and have any speed.

What has been everyone's experience with this? Little to no difference or big difference in speed after the mods. I don't plan on buiding a deck that will turn it into a "bass boat" but something that will allow a little more functionality.

And one more thing that concerns me...I am concerned about how much water the wood will retain over time and add weight if the wood soaks up any water through the carpet. I really want to do these few mods to my boat but I don't want to sacrifice a ton of power in doing it.

Please keep in mind that I am a NEW boat owner and still learning a lot concerning outboard motors and the workings of everything.

Thanks for your help!!!

 

[MiClayton38]

Anyone?????

 

[huntingbronco]

I have a 14ft v-bottom running with a 10 hp. I can make 15mph with just me in it. When I throw another person and some gear in it, that top speed drops to 10mph. You need to add up the weight and see what it amounts to. If significant, like 150# plus, you will see a meaningful drop in speed with a 15hp motor from your current empty speed. Just throw the same weight in the boat now and take it out and see. You will know exactly how it will behave with the additional weight.

As for preparation of wood - there are a lot of great posts to read here. Given wood and water have an affinity for each other, the best defense seems to be to allow for drainage and cover the boat when not being used. Also, avoid "treated" lumber. If you can avoid wood, even better. Wood will provide many years of service, whereas Aluminum should last forever. When I did my boat, I could not avoid the use of wood. I simply primed and painted and provided lots of drainage. However, my boat will sit stored in a barn 48 weeks of the year. I am not worried about water damage at this point.

Hope that helps. Be patient, lots of helpful people on line here.

Get some pictures of your boat up and some more details about your plans and you will get more feedback.

 

[Jonboat Jerry]

Clayton38, as HuntingBronco mentioned, weight is your enemy and the smaller the boat, the more critical it becomes.
First, I would check the transom to find the Mfr spec for capacity. If possible, get the boat weighed (couple of small scales, garbage dump scales, etc) and determine how much capacity you have available.
A boat will get heavier as the wood absorbs water and this is why many users prefer to avoid using it.
When making a modification, consider the weight it will add and go from there. Hope this helps and yes I'm a fanatic about weight.

 

[reedjj]

I built a deck on my boat exactly like what you are talking about. It extends past the existing front seat and stops short of the middle bench to allow for someone to sit there. Mine also opens up for storage. I used 2x2's and 11/32 plywood sealed with 3 coats of spar urethane. I used the minwax brand helmsman spar urethane in a spray can. 3 coats paying special attention to any edges or areas that have cuts or screw holes. I also put another coat on after it was assembled. I then painted mine OD green. But if your going to carpet it there is no need to paint. Just glue and staple the carpet down.

I put in a floor made of 11/32nds ply as well. I put foam boards beneath the wood to keep things quiet and to support the wood between the ribs to prevent bowing. A lot of guys don't attach the floors and don't have any problems. I used 2" wide strips of adhesive velcro applied to the ribs to hold my floor down and also to pad the wood from the ribs so they don't bang around when hitting wakes or waves. my front deck is assembled using galvanized "L" bracket fasteners with galvanized and stainless screws. It is attached to the floor with the same brackets and held down to the front seat with the velcro. IT DOES NOT MOVE! I cant comment on the performance of a 1648 with a 15hp. I will say that my boat has a 25hp motor and it does not matter if Its just me by myself with no gear or I have 1 or 2 people in it. It still does 30mph. Add a third 175 lb person it slows to 28mph. With 4 adults totaling 750lbs just in people (not counting floor, decks, cooler, motor, 6 gallons of gas) which is over the weight limit it slows to 25mph. Only a 5 mph difference with adding over 750lbs.

A small font deck and some floors won't hurt you at all. Just don't use some crazy 3/4ply You don't need to. 11/32nd, 15,32nds or 1/2inch will be fine.

You can check out my build here... https://www.tinboats.net/forum/viewtopic.php?f=21&t=17299

a few lessons I learned are. Do NOT use treated wood. Make sure to use closed cell foam (pink foam). Use stainless hardware.